When a plant, such as a tree, a bush or a shrub, is harvested for transplanting or transplanted from one place to another, it is advisable to leave a certain amount of soil around a root system of the plant. This network of roots and the soil clinging to the roots is known as a root ball, no matter the size or shape. This root ball is necessary to provide protection, moisture and nutrients to the roots.
Many growers start growing plants in containers rather than in the ground, or transplant saplings or semi-mature plants from the ground into containers to mature. Further, a plant may be transplanted from smaller containers into larger containers once the plant outgrows the smaller container. Also, a plant may be transplanted from the ground into a container for transportation to a local distributor or end user. In each instance, the root ball is usually maintained, but additional soil must be added to the container to fill any gaps and voids between the root ball and the container to protect the roots and support the plant in the container. This soil may be a clean soil or may contain various additives.
Plant containers come in various sizes to accommodate the root balls of various size plants. For example, a three gallon container can be ten inches in diameter and a fifteen gallon container can be seventeen inches in diameter. The root ball plus the amount of soil necessary to fill these containers makes the containers heavy. For example, a semi-mature Queen Palm tree, approximately 60 inches high, in a fifteen gallon container may weigh around 80 pounds. The excessive weight makes the plant difficult to move and transport, raising the risk of injury for those moving the plant. Further, the excessive weight makes the plant expensive to ship, as shipping costs increase with increasing weight.
Further still, soil in a plant container can be messy. The soil may spill from the container during shipping and handling, often due to vibration that occurs during loading and transit of the plant. This may cause damage to the roots of the plant and/or spillage of soil from the top of the container. Also, if enough soil spills from the container, the plant itself may shift in the container. Such shifting could damage roots, branches or surrounding plants. Spilled soil may also cause a mess in the shipping vehicle, leading to safety concerns and cleanup costs. If the plant is being transplanted indoors, for example, into a hotel or mall, any spilled soil may damage floors or carpets. Also, damage often occurs to the roots of the plant when removing the root ball from the container, as well as when moving the root ball to its final location.
When transplanting a plant into a container, either from the ground or a smaller container, the extra soil may be added by a mechanized means or, more commonly, manually, both of which can be time intensive. For larger containers, the container must be filled with soil and the plant is then planted into this soil. Depending on the number of plants to be transplanted, this may take considerable time and require many workers.